As a method for producing an oxadiazolinone compound, there is known a method in which a 2-aryl-substituted hydrazinecarboxylic acid methyl ester is treated with phosgene to give a 2-(chlorocarbonyl)-2-aryl-substituted hydrazinecarboxylic acid methyl ester, which is then cyclized by the action of a base (for example, refer to JP-B-60-19302). However, such a method uses phosgene having strong toxicity, which requires facilities provided with safety measures for industrial practice.